01 August 2007

Virus 'hybrids' can act as nanoscale memory devices

NewScientistTech reports on a fascinating mash-up of viruses and quantum dots (nanoscale spheroids of selected materials including semiconductor atoms which yield remarkable electro-optic properties due to quantum containment effects). This research was performed at the University of California, Riverside, and published in a paper entitled "Microscale memory characteristics of virus-quantum dot hybrids" in Applied Physics Letters.

A new type of memory device has been made by researchers in the US and Italy by attaching individual viruses to tiny specks of semiconducting material called quantum dots. The "hybrid" material could be used to develop biocompatible electronics and offer a cheap and simple way to make high-density memory chips, the researchers say... "Interactions between organic and inorganic particles are quite fascinating," team leader [Mihri] Ozkan told New Scientist. "In our case, finding the memory effect was quite unexpected because each nanoparticle does not have any memory characteristics on its own, but only when connected as a hybrid."
Non-volatile memory
Ozkan and co-workers began by depositing cosahedral cowpea mosaic viruses (CPMV) on quantum dots (made of cadmium selenide and zinc sulphide) using different binding sites on the virus' capsid, or outer shell. CPMV, a plant virus that is harmless to humans, is about 30 nanometres across and consists of a capsid with an RNA core. Next, the researchers embedded the hybrids into a polymer matrix and sandwiched them between two conducting electrodes for testing. They found that each hybrid unit can be operated as a memory device with conductive states that can be switched between high and low, corresponding to a 1 and a 0, by applying a low voltage. These states are "non-volatile", meaning data is stored even when the power is switched off.
Remarkable.

2 comments:

Mark23 said...

I love reading these blogs. It makes me extremely knowledgeable

Scott Jordan said...

Well thank you, Mark! I enjoy writing them. In fact, I have a post or two for tonight... check back soon!